According to McClelland, most people possess and portray a mixture of these characteristics. Some people display a strong bias toward a particular motivational need which, in return, influences their behavior and influences their working/management style. McClelland believed that those who resembled the "affiliation motivation model" had diminished objectivity as a manager. He attributed this weakness to their need to be accepted and liked, which can impair decision making. A person who fits the "authority motivation model" is more devoted to an organization, and also possesses a better work ethic. Those who seek power within a leadership role may not even know how to get along with others and how to compromise. Lastly, individuals who fit the "achievement model" are more likely to be overachieving and overbearing. These types of people prefer tasks that are challenging and also prefer to work alone. McClelland also believed that an individual's need grouping changes as they grow, and those who do not naturally possess specific needs can acquire them through training and experience